The composition of tungsten heavy alloys are known in the art have a tungsten content of from about 88% to about 98% by weight, balance nickel and iron. In conventional prior processes used to produce the preferred tungsten heavy alloys resulted in materials having spherical tungsten grains of at least 30 micrometers in diameter as a discontinuous phase and surrounded by a continuous matrix phase of nickel, iron and tungsten. When tungsten heavy alloys are used as kinetic energy penetrators they are generally mechanically worked to increase the hardness of the penetrator. With conventional working methods the reduction in area is generally in the 7% to 25% range. Working beyond 25% resulted in the generation of defects at the matrix tungsten interface. The aspect ratio of the tungsten grains in the material worked in this manner is generally no greater the about 1:2.
It is believed, therefore, that a tungsten heavy alloy material containing from about 60% to about 98% tungsten and having improved properties, in particular, a higher recrystallization temperature, that is above about 1000.degree. C., and a unique microstructure, namely a continuous phase of tungsten and a discontinuous phase of a tungsten-nickel-iron alloy having grains with an aspect ratio greater than about 4:1 relatively uniformly dispersed thoughout the continuous tungsten phase and wherein the nickel to iron weight ratio in the tungsten heavy alloy is from about 6:4 to about 9:1, which alloy has a high impact strength and improved machinability would be an advancement in the art.